Processing facilities and other facilities routinely include tanks for storing liquid materials and other materials. For example, storage tanks are routinely used in tank farm facilities and other storage facilities to store oil or other materials. As another example, oil tankers and other transport vessels routinely include numerous tanks storing oil or other materials. Processing facilities also include tanks for implementing an industrial process, such as receiving material through an input of the tank while allowing material to leave through an output of the tank.
Often times, it is necessary or desirable to measure the amount of material stored in a tank, for example, in order to control the level of material in the tank to be at desired level during an industrial process of receiving or releasing material in the tank. Radar gauges are used to measure an amount of material stored in a tank. Radar gauges typically transmit signals towards a material in a tank and receive signals reflected off the material in the tank.
Unfortunately, radar measurements can be affected by multiple reflections inside a tank, such as reflections from the tank's walls, bottom, roof, and obstructions like agitators, ladders, and heat coils. In some situations, false echoes associated with signals reflected off objects other than the material in a tank can interfere with the actual reflection of signals off the material in the tank, causing inaccuracies in level measurements.
Moreover, the full capacity of a tank is often used for storage and transfer, and level measurements typically need to be constantly reliable even as the level of material approaches the bottom or roof of the tank. This can be difficult to achieve with conventional radar gauges.